High-intensity ultrasonic exfoliation-assisted rapid preparation of MXene for gas sensing.

• This work proposes a new method for the rapid preparation of MXenes. • It takes only 3 h to etch the MAX phase by the HIUE method to obtain MXene. • Ti 3 C 2 T x etched by the method can be used as an effective nanocomposite substrate. • Ti 3 C 2 T x etched by the method show good selectivity and excellent response to NH 3. MXenes are widely studied two-dimensional materials and have been attracting increasing research attention on exploring their applications. However, the preparation for MXene materials is still cumbersome and time-consuming, significantly limiting their utilization. In this work, a high-intensity ultrasonic exfoliation (HIUE) environment is constructed for efficient preparation of the Ti 3 C 2 T x -MXene, which drastically shortens the etching time to 3 h with a yield of more than 90 % after adjusting the temperature, dosage, and ultrasonic power. The delamination of the MXene occurs during etching due to the ultrasound, which promotes the yield of few-layered MXenes of 20 % in one step after centrifuging. The characteristics of the HIUE-prepared MXenes are compared with those obtained by conventional wet etching methods. The feasibility of the proposed HIUE method is further verified by constructing MXene-based nanocomposites and exploring their gas-sensing applications. The as-prepared Ti 3 C 2 T x MXene obtained by the proposed rapid preparation method show good selectivity and an excellent response of 21.1 % to 100 ppm NH 3. In contrast, the MXene/MoS 2 nanocomposites obtained by the rapid preparation method also exhibit enhanced gas-sensing performance. Such experiments demonstrate the efficiency and the excellent potential for rapid preparation and compositing of MXene-based materials by the proposed HIUE method. [ABSTRACT FROM AUTHOR]